The purpose of this study is to investigate both the efficacy and safety of sintilimab combined with bevacizumab and radiotherapy in advanced hepatocellular carcinoma.

Inclusion Criteria:

1. Age 18-75 years;

2. Eastern Cooperative Oncology Group (ECOG) performance status score of 0 or 1;

3. Treatment-naïve primary HCC (consistent with the American Association for the Study of Liver Diseases 2018 Guideline on Liver Cancer Diagnosis (18)) or initial recurrent HCC after radical resection without any postoperative anti-cancer treatment;

4. At least one measurable lesion in the liver on the basis of modified Response Evaluation Criteria in Solid Tumors (mRECIST);

5. Presented with Cheng's type I/II/III PVTT;

6. Largest tumor size ≤ 10 cm, number of tumors ≤ 3, and remnant liver volume ≥ 50%;

7. Child-Pugh class A;

8. Adequate hematological, liver, renal function:

   1. hemoglobin concentration ≥ 90 g/L;
   2. neutrophil count ≥ 1.5×109/L;
   3. platelet count ≥ 60×109/L;
   4. AST and ALT ≤ 3×upper limit of normal (ULN)
   5. total bilirubin ≤ 1.5×ULN;
   6. serum creatinine ≤ 1.5×ULN;
   7. serum albumin concentration ≥ 30 g/L;

9. Life expectancy of at least 3 months.

Exclusion Criteria:

1. Tumor invasion of the superior mesenteric vein or bile ducts;
2. Infiltrative HCC;
3. Allergic to research reagents;
4. With other malignancies within 5 years;
5. With poorly controlled hypertension;
6. A past medical history of hepatic decompensation, such as hepatic encephalopathy, refractory ascites, and esophageal or gastric variceal bleeding;
7. A history of autoimmune disease;
8. Active infection requiring systemic treatments;
9. Severe bleeding;
10. With diseases needing daily non-steroidal anti-inflammatory drug (NSAID) therapy;
11. With other severe comorbidities.